物质都是由肉眼看不见的微粒构成的。下列关于物质的构成叙述错误的是（  ）

根据短文理解，回答下列各题。

      CCTV reported that every year Chinese people throw away a lot of food; it can feed 200 million people for a year.

      Do we have too much food? Of course not. According to the UN World Food Program, there were 925 million hungry people around the world in 2010. Six million children die of hunger every year.

      Luckily, a number of people have realized the importance of saving food. Last November, Li Hong, a waitress in a restaurant in Nanjing, lost her job because she took some leftover(剩余的)food home for her son. Many people are by her side and criticized(批评)the waste behavior.

      What should we do in our daily life to waste less food? Here are some tips:

       ①Don't order too much food in a restaurant. Only order as much as you want to eat. If you cannot eat all the food you order, take the rest of it home.

       ②Don't be too picky(挑剔的)about food. Some food may not taste great, but your body needs it.

       ③Don't keep too much food at home, especially vegetables and fruit.

     “Every grain on the plate comes from hard work(谁知盘中餐, 粒粒皆辛苦).” It tells us everybody must save food.

【保障合法权利】日前，长沙市下发《关于长沙市2014年春季中小学收费标准的通知》，规定今年春季，长沙市城乡公办学校义务教育阶段收费，继续实行免收“一费制”范围内的杂费、课本费、作业本费，学生只需缴纳少量自愿选择的服务性收费；对在该市就读义务教育阶段执行公办学校收费标准的外来务工就业人员子女与本市户口学生入学收费一视同仁。
从上述材料中你感悟到国家在保障我们的什么权利？该项权利同时也是公民的义务，请你谈谈作为中学生，应该怎样履行好这一义务？

下图为某城市三种行业付租能力随距离变化示意图，该城市规模扩大和地价上涨将导致（   ）

设${\left(2-x\right)}^6=a_0+a_{1}x+a_{2}x+\cdots +a_{6}x$,则$\left|a_1\right|+\left|a_2\right|+\cdots +\left|a_6\right|$的值是 （    ）